Spark plug



- lMmh 29, 1927'.

A. BOURRIEU SPARK PLUG Filed Aug. 4, 1923 Patented Y Mar. 29, 19.27.

yUNITED STATEs 1,622,760 PATENT OFFICE.

ALBERT BOUBRIEU, 0F CHICAGO, ILLINOIS.

SPARK PLUG.

Application led August 4, 1923. Serial No. 655,676.

v mercury.

Another object of thc invention is to provide a spark plug which will have one of its electrodes hollowed out and adapted to receive a supply of mercury and will also bel provided with spaced. grooved electrodes in sparking relation with said first. mentioned electrode.y s

A further object of the invention is to provide a suitable spark plug for internal combustion engines which will be highly efficient in use and quite inexpensive to manufacture.

A further object is to provide means to keep the center pin ot the spark plug free from all carbon or-rust at all times, so that the point of contact is always clear.l

Other objects will appear as the descrip'- tion proceeds.

-ln the accompanying drawing which forms 'a part ot my 'application7 The single figure represents a `transfer sectional view through 'my improved spark plug. c

Like characters of reference are used throughout the following specification and the accompanying drawings to designate cor-- responding parts.

The body or shell 1 of the spark plug is provided adjacent its upper ends with the internal screw threads 2 and at its lower end with the centrally extending inclined seat 3.

A hollow insulator 4 is provided at its lower end with the enlarged portion 5 which is adapted to seat down on the asbestos copper washer 6 on the 'seat 3. A second washer 7 is positioned on the upper shoulder y of the enlarged portion 5 and is securely clamped together with said insulator by means of the exteriorly screw threaded nut 8.

A central rod or electrodev9 is provided adjacent its lower end with the iange 10, whichk is adapted to seat in a correspondingly shaped socket at the lower end ot the insulator and is further provided at its extreme lower end with the threaded extension 11. This rod or electrode 9 extends up through the central portion ot the insulator 4 and somewhat above the same and is. screw threaded as at 12 at its upper extremity. An asbestos washer 13 is positioned about the 4rod-or electrode 9 and a portion thereof is snugly fitted into the interior opening in the lnsulator 4. A brass washer 14 ispsitioned about said 'electrode 9 and -on top of the l asbestoswasher 13 and is securely clamped down by means of the locking nut 15. A suitable binding post nut 16 is threaded on the threaded extremity 12 of theelectrode 9 and serves to clamp the ignition wires in position thereon.

The electrode 9 has also connected with it a lower portion or hollow tube 17 which is interiorly threaded at its upper end land adapted to the threaded extension 11, of the said electrode. The tube `17 is adapted to hold a quantity of mercury 18 the action of wlixch will later be explained. threaded into the lower end ofthe shelll of the spark plug and are bent inwardly and then outwardly adjacent their lower extremities. The lower ends of the electrodes 19 are grooved'asat 20 on the sides adjacent the hollow tube 17.

The action of the plugI will be as Vfollowst-When the high tension current passes through the mercury it will cause the same to permeate by reason of the electrons passdrop off leaving the sharp edges at the op`` posite sides otv said grooves always clean and ready for efficient sparking between the same and the negative electrode.

' There will be a vacuum inside of the porcelain insulator which will prevent .the expansion and cracking of the said insulator which is often caused by the over-heating of the same. Many minor changes in detail of construction may be resorted to without departure from the spirit of the invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. A spark plug comprising a shell, a holpair of positive electrodes 19 are ing through the mercury.. and pores of the vsteel walls of the tube.

low insulator carried thereby, an electrode adapted to extend through said insulator,

the interior portion of said insulator beingy exhausted of air, a mercury lled'tube de'- tachably secured to the lower end of said electrode and a pair of grooved positive electrodes adjacent the lower end of said mercury iilled tube. v

2. In a spark plug, the combination with a shell, of a hollow insulator, an electrode adapted to extend through said insulator, an asbestos washer positioned partly within the top of the insulator, of means for, clamping said washer in place, the hollow insulator 15 being exhausted of air adapted to prevent 'adapted to extend through `the* expansion and cracking of'sad insulatorv by overheating. l

3. In a spark lug, the combination with a shell, of a hol ow insulator, an electrode p y said insulator, a

mercurylled tube detae ably secured to the lower end of said electrode, the mercur .iilled tube having a relatively thin wal adapted to enable mercury vapor causedvby high temperature to ermeate through .the

walls of the central e ect-rode. thereby causing accumulated carbon to dissolve'.

n testimony whereof'he aixes his signa- ALBERT BOURRIEU.

ture. 

